import turtle as t
import time 
t.setup(900,400)
t.pencolor('green')
t.speed(0)
t.tracer(0)
t.goto(450,0)
s = t.textinput('输入弹幕','请输入弹幕内容')
size = int(t.numinput('输入字号','请输入弹幕大小'))
while 1:
    t.write(s,font=("思源黑体",size,"bold"))
    time.sleep(0.01)
    t.clear()
    t.penup()
    t.backward(1)
    t.pendown()
t.done()